105 أسطر
2.5 KiB
Markdown
105 أسطر
2.5 KiB
Markdown
# Postmortem Report
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## Incident Summary
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On July 28, 2026, the application experienced repeated OOMKilled events, causing service interruption for approximately 45 minutes. During this period, users were unable to access the application.
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---
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## Timeline
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- 10:00 AM - Application deployed successfully.
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- 10:12 AM - Memory usage started increasing.
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- 10:18 AM - First OOMKilled event occurred.
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- 10:20 AM - Kubernetes restarted the container.
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- 10:24 AM - Multiple OOMKilled events repeated.
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- 10:45 AM - Monitoring system alerted the operations team.
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- 11:00 AM - Memory limit increased and memory leak fixed.
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- 11:03 AM - Service fully restored.
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---
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## Root Cause
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The application contained a memory leak that caused continuous memory consumption. The container exceeded its memory limit, resulting in repeated OOMKilled events and continuous restarts.
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---
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## Recommendations
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- Set appropriate memory requests and limits.
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- Enable Horizontal Pod Autoscaler (HPA).
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- Monitor memory usage continuously.
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- Configure alerting before memory reaches critical levels.
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- Perform load testing before production deployment.
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---
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# Auto Scaling Policy
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## Objective
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Prevent service interruption caused by high memory usage and repeated OOMKilled events.
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## Scaling Policy
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- Minimum Replicas: 2
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- Maximum Replicas: 10
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### Scale Out
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Increase the number of containers when:
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- CPU usage > 70% for 2 minutes.
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- Memory usage > 75% for 2 minutes.
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Increase by 2 replicas at a time.
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### Scale In
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Decrease the number of containers when:
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- CPU usage < 40% for 10 minutes.
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- Memory usage < 50% for 10 minutes.
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Remove only one replica at a time.
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### Additional Protection
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- Configure memory requests and limits.
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- Enable readiness and liveness probes.
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- Prevent scheduling on unhealthy nodes.
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---
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# Early Detection Using Cloud Monitoring
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The issue can be detected early using cloud monitoring tools by continuously monitoring application and infrastructure metrics.
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## Metrics to Monitor
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- Memory Usage
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- CPU Usage
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- Container Restarts
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- OOMKilled Events
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- Pod Status
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- Application Response Time
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## Alerts
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Configure alerts when:
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- Memory usage exceeds 80%.
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- Container restarts more than 3 times within 5 minutes.
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- OOMKilled event is detected.
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- Response time exceeds 500 ms.
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## Monitoring Tools
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- Prometheus
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- Grafana
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- Kubernetes Metrics Server
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- Cloud Monitoring Platform
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These tools provide dashboards, real-time metrics, and alert notifications to help engineers respond before the service becomes unavailable.
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